The present invention relates to novel therapeutic and diagnostic systems. More particularly, the present invention is directed to dendrimer based multifunctional compositions and systems for use in disease diagnosis and therapy (e.g. cancer diagnosis and therapy). The compositions and systems generally comprise two or more separate components for targeting, imaging, sensing, and/or triggering release of a therapeutic or diagnostic material and monitoring the response to therapy of a cell or tissue (e.g., a tumor).
New initiatives in chemotherapeutics and radiopharmaceutics have improved the survival of patients with many forms of neoplasm. Several cancers now have five year survival rates greater than 80 percent. However, despite these successes, many problems still exist concerning cancer therapy. For example, many common neoplasms, such as colon cancer, respond poorly to available therapies.
For tumor types that are responsive to current methods, only a fraction of cancers respond well to the therapies. In addition, despite the improvements in therapy for many cancers, most currently used therapeutic agents have severe side effects. These side effects often limit the usefulness of chemotherapeutic agents and result in a significant portion of cancer patients without any therapeutic options. Other types of therapeutic initiatives, such as gene therapy or immunotherapy, may prove to be more specific and have fewer side effects than chemotherapy. However, while showing some progress in a few clinical trials, the practical use of these approaches remains somewhat limited at this time.
Despite the limited success of existing therapies, the understanding of the underlying biology of neoplastic cells has advanced. The cellular events involved in neoplastic transformation and altered cell growth are now identified and the multiple steps in carcinogenesis of several human tumors have been documented (See e.g., Isaacs, Cancer 70:1810 [1992]). Oncogenes that cause unregulated cell growth have been identified and characterized as to genetic origin and function. Specific pathways that regulate the cell replication cycle have been characterized in detail and the proteins involved in this regulation have been cloned and characterized. Also, molecules that mediate apoptosis and negatively regulate cell growth have been clarified in detail (Kerr et al., Cancer 73:2013 [1994]). It has now been demonstrated that manipulation of these cell regulatory pathways has been able to stop growth and induce apoptosis in neoplastic cells (See e.g., Cohen and Tohoku, Exp. Med., 168:351 [1992] and Fujiwara et al., J. Natl. Cancer Inst., 86:458 [1994]). The metabolic pathways that control cell growth and replication in neoplastic cells are important therapeutic targets.
Despite these impressive accomplishments, many obstacles still exist before these therapies can be used to treat cancer cells in vivo. For example, these therapies require the identification of specific pathophysiologic changes in an individual""s particular tumor cells. This requires mechanical invasion (biopsy) of a tumor and diagnosis typically by in vitro cell culture and testing. The tumor phenotype then has to be analyzed before a therapy can be selected and implemented. Such steps are time consuming, complex, and expensive.
There is a need for treatment methods that are selective for tumor cells compared to normal cells. Current therapies are only relatively specific for tumor cells. Although tumor targeting addresses this selectivity issue, it is not adequate, as most tumors do not have unique antigens. Further, the therapy ideally should have several, different mechanisms of action that work in parallel to prevent the selection of resistant neoplasms, and should be releasable by the physician after verification of the location and type of tumor. Finally, the therapy ideally should allow the physician to identify residual or minimal disease before and immediately after treatment, and to monitor the response to therapy. This is crucial since a few remaining cells may result in re-growth, or worse, lead to a tumor that is resistant to therapy. Identifying residual disease at the end of therapy (i.e., rather than after tumor regrowth) would facilitate eradication of the few remaining tumor cells.
Thus, an ideal therapy should have the ability to target a tumor, image the extent of the tumor and identify the presence of the therapeutic agent in the tumor cells. It ideally allows the physician to determine why cells transformed to a neoplasm, to select therapeutic molecules based on the pathophysiologic abnormalities in the tumor cells, to activate the therapeutic agents only in abnormal cells, to document the response to the therapy, and to identify residual disease.
The present invention relates to novel therapeutic and diagnostic systems. More particularly, the present invention is directed to dendrimer based multifunctional compositions and systems for use in disease diagnosis and therapy (e.g., cancer diagnosis and therapy). The compositions and systems generally comprise two or more distinct components for targeting, imaging, sensing, and/or triggering release of a therapeutic or diagnostic material and monitoring the response to therapy of a cell or tissue (e.g., a tumor).
For example, the present invention provides a composition comprising a dendrimer complex, said dendrimer complex comprising first and second dendrimers, the first dendrimer comprising a first agent and the second dendrimer comprising a second agent, wherein the first agent is different than the second agent. In preferred embodiments, the first and said second agents are selected from the group consisting of therapeutic agents, biological monitoring agents, biological imaging agents, targeting agents, and agents capable of identifying a specific signature of cellular abnormality. In some embodiments, the first dendrimer is covalently linked to the second dendrimer. In certain embodiments, the dendrimer complex includes additional dendrimers. For example, in some embodiments, the complex comprises a third dendrimer (e.g., a third-dendrimer covalently linked to the first and second dendrimers). In yet other embodiments, the dendrimer complex comprises fourth, fifth, or additional dendrimers. Each of the dendrimers may comprise an agent.
In some embodiments, the present invention provides a composition comprising: a first dendrimer comprising a first agent; and a second dendrimer comprising a second agent, wherein the first and second dendrimers are complexed (e.g., covalently attached) with at least one dendrimer (e.g., to each other, to a common third dendrimer, or each individually to a third and fourth dendrimers respectively), and wherein the first agent is different than the second agent, and wherein the first and the second agents are selected from the group consisting of therapeutic agents, biological monitoring agents (i.e., agents capable of monitoring biological materials or events), biological imaging agents (i.e., agents capable of imaging biological materials or events), targeting agents (i.e., agents capable of targeting a biological materialxe2x80x94i.e., specifically interacting with the biological material), and agents capable of identifying a specific signature of cellular identity (i.e., capable of identifying a characteristic of a cell that helps differentiate the cell from other cell typesxe2x80x94e.g., a cellular proteins specific for a particular cellular abnormality). The present invention is not limited by the nature of the dendrimers. Dendrimers suitable for use with the present invention include, but are not limited to, polyamidoamine (PAMAM), polypropylamine (POPAM), polyethylenimine, iptycene, aliphatic poly(ether), and/or aromatic polyether dendrimers. Each dendrimer of the dendrimer complex may be of similar or different chemical nature than the other dendrimers (e.g., the first dendrimer may comprises a PAMAM dendrimer, while the second dendrimer may comprises a POPAM dendrimer). In some embodiments, the first or second dendrimer may further comprises an additional agent.
In some embodiments of the present invention, the dendrimer complex may further comprises one or more additional dendrimers. For example, the composition may further comprises a third dendrimer; wherein the third-dendrimer is complexed with at least one other dendrimer. In some embodiments, a third agent is complexed with the third dendrimer. In some embodiments, the first and second dendrimers are each complexed to a third dendrimer. In preferred embodiments, the first and second dendrimers comprise PAMAM dendrimers and the third dendrimer comprises a POPAM dendrimer. In certain embodiments, the present invention further comprises fourth and/or fifth dendrimers comprising agents (e.g., third and fourth agents), wherein the fourth and/or fifth dendrimer is also complexed (e.g., covalently attached) to the third dendrimer. The present invention is not limited by the number of dendrimers complexed to one another.
In some embodiments of the present invention, the first agent is a therapeutic agent and the second agent is a biological monitoring agent. In preferred embodiments, the therapeutic agent includes, but is not limited to, a chemotherapeutic agent, an anti-oncogenic agent, an anti-vascularizing agent, a anti-microbial or anti-pathogenic agent, and an expression construct comprising a nucleic acid encoding a therapeutic protein. In some embodiments, the therapeutic agent is protected with a protecting group selected from photo-labile, radio-labile, and enzyme-labile protecting groups. In preferred embodiments, the chemotherapeutic agents include, but are not limited to, platinum complex, verapamil, podophyllotoxin, carboplatin, procarbazine, mechlorethamine, cyclophosphamide, camptothecin, ifosfamide, melphalan, chlorambucil, bisulfan, nitrosurea, adriamycin, dactinomycin, daunorubicin, doxorubicin, bleomycin, plicomycin, mitomycin, etoposide, tamoxifen, taxol, transplatinum, 5-fluorouracil, vincristin, vinblastin, and methotrexate. In some embodiments, the anti-oncogenic agent comprises an antisense nucleic acid. In certain embodiments, the antisense nucleic acid comprises a sequence complementary to an RNA of an oncogene. In preferred embodiments, the oncogene includes, but is not limited to, abl, Bcl-2, Bcl-x1, erb, fms, gsp, hst, jun, myc, neu, raf; ras, ret, src, or trk. In some embodiments, the nucleic acid encoding a therapeutic protein encodes a factor including, but not limited to, a tumor suppressor, cytokine, receptor, inducer of apoptosis, or differentiating agent. In preferred embodiments, the tumor suppressor includes, but is not limited to, BRCA1, BRCA2, C-CAM, p16, p21, p53, p73, Rb, and p27. In preferred embodiments, the cytokine includes, but is not limited to, GMCSF, IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-11, IL-12, IL-13, IL-14, IL-15, xcex2-interferon, xcex3-interferon, and TNF. In preferred embodiments, the receptor includes, but is not limited to, CFTR, EGFR, estrogen receptor, IL-2 receptor, and VEGFR. In preferred embodiments, the inducer of apoptosis includes, but is not limited to, AdE1B, Bad, Bak, Bax, Bid, Bik, Bim, Harakid, and ICE-CED3 protease. In some embodiments, the therapeutic agent comprises a short-half life radioisotope.
In some embodiments of the present invention, the biological monitoring agent comprises an agent that measures an effect of a therapeutic agent (e.g., directly or indirectly measures a cellular factor or reaction induced by a therapeutic agent), however, the present invention is not limited by the nature of the biological monitoring agent. In some embodiments, the monitoring agent is capable of measuring the amount of or detecting apoptosis caused by the therapeutic agent.
In some embodiments of the present invention, the imaging agent comprises a radioactive label including, but not limited to, 14C, 36CI, 57Co, 58Co, 51Cr, 125l, 131l, 111ln, 152Eu, 59Fe, 67Ga, 32P, 186Re, 35S, 75Se, Tc-99m, and 169Yb, however, the present invention is not limited by the nature of the imaging agent.
In some embodiments of the present invention, the targeting agent includes, but is not limited to an antibody, receptor ligand, hormone, vitamin, and antigen, however, the present invention is not limited by the nature of the targeting agent. In some embodiments, the antibody is specific for a disease specific antigen. In some preferred embodiments, the disease specific antigen comprises a tumor specific antigen. In some embodiments, the receptor ligand includes, but is not limited to, a ligand for CFTR, EGFR, estrogen receptor, FGR2, folate receptor, IL-2 receptor, glycoprotein, and VEGFR.
The present invention also provides methods for treating a cell with a dendrimer complex comprising: providing a cell and a composition comprising a dendrimer complex, and exposing the cell to the dendrimer complex. In some embodiments, the dendrimer complex comprises a first dendrimer comprising a first agent, and a second dendrimer comprising a second agent, wherein the first and second dendrimers are complexed with at least one dendrimer, and wherein the first agent is different than the second agent, and wherein the first and the second agents are selected from the group consisting of therapeutic agents, biological monitoring agents, biological imaging agents, targeting agents, and agents capable of identifying a specific signature of cellular abnormality; and exposing the cell to the composition. The present invention is not limited by the nature of the cell type or the exposing step. For example, cells of the present invention include, but are not limited to, cell residing in vitro (e.g., cell culture cells) and cells residing in vivo (e.g., cells of a human or animal subject or pathogenic cells). In preferred embodiments, where the cell resides in a subject (e.g., a human or animal subject), the subject has a disease (e.g., the cell is a disease cell such as a tumor cell). In some embodiments, the disease includes, but is not limited to, cancer, cardiovascular disease, inflammatory disease, and prion-type disease (i.e., diseases associated with or caused by a prion).
In some embodiments of the present invention, the therapeutic agent is in inactive form and is rendered active following administration of the composition to the subject. For example, the agent, upon exposure to light or a change in pH (e.g., due to exposure to a particular intracellular environment) is altered to assume its active form. In these embodiments, the agent may be attached to a protective linker (e.g., photo-cleavable, enzyme-cleavable, pH-cleavable) to make it inactive and become active upon exposure to the appropriate activating agent (e.g., UV light, a cleavage enzyme, or a change in pH).
In some embodiments of the present invention, the subject has a tumor or is suspected of having cancer. In certain embodiments the cancer includes, but is not limited to, lung, breast, melanoma, colon, renal, testicular, ovarian, lung, prostate, hepatic, germ cancer, epithelial, prostate, head and neck, pancreatic cancer, glioblastoma, astrocytoma, oligodendroglioma, ependymomas, neurofibrosarcoma, meningia, liver, spleen, lymph node, small intestine, colon, stomach, thyroid, endometrium, prostate, skin, esophagus, and bone marrow cancer. In some embodiments, compositions comprising nanodevices, and any other desired components (e.g., pharmaceutically acceptable carriers, adjuvants and exipients) are administered to the subject. The present invention is not limited by the route of administration. Such administration routes include, but are not limited to, endoscopic, intratracheal, intralesion, percutaneous, intravenous, subcutaneous, and intratumoral administration.